Repetsky S P, Vyshyvana I G, Kruchinin S P, Bellucci Stefano
Institute of High Technologies, Taras Shevchenko National University of Kiev, 4-g, Academician Glushkov Ave., Kiev, 03022, Ukraine.
Bogolyubov Institute for Theoretical Physics, NASU, Kiev, 03143, Ukraine.
Sci Rep. 2018 Jun 14;8(1):9123. doi: 10.1038/s41598-018-26925-0.
In the one-band model of strong coupling, the influence of substitutional impurity atoms on the energy spectrum and electrical conductance of graphene is studied. It is established that the ordering of substitutional impurity atoms on nodes of the crystal lattice causes the appearance of a gap in the energy spectrum of graphene with width η|δ| centered at the point yδ, where η is the parameter of ordering, δ is the difference of the scattering potentials of impurity atoms and carbon atoms, and y is the impurity concentration. The maximum value of the parameter of ordering is [Formula: see text]. For the complete ordering of impurity atoms, the energy gap width equals [Formula: see text]. If the Fermi level falls in the region of the mentioned gap, then the electrical conductance [Formula: see text] at the ordering of graphene, i.e., the metal-dielectric transition arises. If the Fermi level is located outside the gap, then the electrical conductance increases with the parameter of order η by the relation [Formula: see text]. At the concentration [Formula: see text], as the ordering of impurity atoms η →1, the electrical conductance of graphene [Formula: see text], i.e., the transition of graphene in the state of ideal electrical conductance arises.
在强耦合单带模型中，研究了替代杂质原子对石墨烯能谱和电导率的影响。结果表明，晶格节点上替代杂质原子的有序排列会导致石墨烯能谱中出现一个宽度为η|δ|的能隙，该能隙以yδ点为中心，其中η是有序参数，δ是杂质原子与碳原子散射势的差值，y是杂质浓度。有序参数的最大值为[公式：见原文]。对于杂质原子的完全有序排列，能隙宽度等于[公式：见原文]。如果费米能级落在上述能隙区域内，那么在石墨烯有序排列时电导率[公式：见原文]，即发生金属 - 介电转变。如果费米能级位于能隙之外，那么电导率随有序参数η按[公式：见原文]的关系增加。在浓度[公式：见原文]时，随着杂质原子有序排列η → 1，石墨烯的电导率[公式：见原文]，即石墨烯转变为理想电导率状态。
